Web Accessibility Guidelines
Make sure to check my blogpost Web Accessibility Guidelines 2022 Update
Ideally, applying a11y (accessibility) guidelines should be a part of the development process, rather than an afterthought.
I propose the following steps:
Steps to perform an a11y audit
1/ Automatic testing
There are a handful of these types of tools. All of them run an audit check and provide a list of things to change. These tools are described here in more detail: https://a11y.coffee/start-testing
WAVE Web Accessibility Evaluation Tool: in my opinion it is the tool that gives a quickest and most visual overview. I’d start here. https://wave.webaim.org/
Additional tools that provide similar information:
Firefox a11y audit in Firefox developer tools (recommended)
In a11y dev tools tab, select: “All issues”, “show tabbing order”, and color deficiency simulations
Chrome's lighthouse audit in chrome developer tools
Axe browser extension https://www.deque.com/axe/
In my opinion, running one of the above should be enough to cover this point.
2/ A11y checklist
Use an a11y checklist to discover issues that automated tools might have overlooked: https://www.a11yproject.com/checklist or https://webaim.org/standards/wcag/checklist
3/ Manual testing
Cross-check the following use cases:
Interactive elements should follow ARIA guidelines: https://www.w3.org/TR/wai-aria-practices/
Each page should be keyboard navigable
Each page should be screen reader navigable (navigate with closed eyes using keyboard and a screen reader)
Focus styles should be apparent
Touch points should have appropriate dimensions on touch device sizes: 48x48pt minimum for touchable areas, and 32pt of space in between touchable elements
View site in grayscale, make sure it is readable (use nocoffee from the resources section)
View site in high contrast mode, make sure it is readable (use nocoffee from the resources section)
View site at 200% magnification
Resources
General resources
https://www.w3.org/TR/wai-aria-practices/ Main resource for WAI-ARIA guidelines
https://a11y.coffee Quick intro to the concept of a11y
https://webaim.org/techniques/skipnav Skip navigation link
https://webaim.org/techniques/css/invisiblecontent Invisible content for screen readers
https://css-tricks.com/accessible-svgs A11y for svg
Tools and extensions
Microsoft accessibility insights, can be also used to test a11y for desktop and mobile apps
https://accessgarage.wordpress.com/2013/02/09/458/ (download chrome extension nocoffee and use it to simulate different levels of visual impairment)
https://chrome.google.com/webstore/detail/screen-reader/kgejglhpjiefppelpmljglcjbhoiplfn Screen reader chrome extension (annoying, will force you to reinstall / uninstall each time to keep your sanity)
https://marketplace.visualstudio.com/items?itemName=MaxvanderSchee.web-accessibility VSCode extension
Checklists
Courses
The NoCoffee extension for Chrome seems gone. For high contrast mode, you can use this High Contrast extension for Chrome